8/18/2011 11:20 AM PDT

HUGE twist in the case involving a brutal knockout punch in front of a Hollywood nightclub in May -- the victim was so drunk and belligerent ... the charges against the puncher were just drastically reduced.

Eduardo Lopez will not be prosecuted for felony battery ... so said the judge at the end of his preliminary hearing this AM. Hizzoner just knocked the charge down to a misdemeanor.

Turns out ... the victim, Erick Kernel-Sanchez, had an astronomical blood alcohol level -- .29, more than 4 times the legal limit. Get this ... a .30 can lead to unconsciousness or even death.

In addition, authorities testified the victim was under the influence of marijuana and was extremely belligerent ... so belligerent, he tried to fight the paramedics and nurses when he arrived at the hospital.

The TMZ fight video was Exhibit A in court, but despite the brutal knockout -- which left Erick with a subdural hematoma and skull fractures -- the judge determined Erick was partly to blame.